Actually, again, the analogy only works if first there is risk involved. For instance, if you have to pay $60 for the right to reach down for that $100, and you only get one shot at it, and it's windy, then there would be a risk. Maybe you practice beforehand and figure out you can grab it over 60% of the time, and thus should expect to make money with each attempt.
Then you lower the $100 to $75, so you are wagering $60 for the right to snag $75 off the ground. In that case, if you can't grab that money 80% of the time before it flies away in the wind, you would end up losing money in the proposition.
The developer has to put their own money on the table with the hopes of generating a profit down the road. A larger affordable housing requirement means that is a bite out of the expected profit. Then there are rising costs in labor, materials, possible court battles, and every other delay that developers need to go through to actually get a project built around here. At some point many will say that while they would probably still make a profit, it becomes less clear cut with every regulation added on top of what they're doing. If you go to the above, nobody is going to wager $60 for the chance to pick up $65. There is a point where it isn't worth it anymore. Developers risk a ton of their own money and that risk has to be part of any analogy for it to actually apply here.